Hamamatsu-photonics K.k.

Hiroki Suzuki

Koei Yamamoto

Naoto Sakurai

Shigeyuki Nakamura

Shunsuke Adachi

Yuichi Miyamoto

Tsuyoshi Ohta

Michito Hirayanagi

Toshihiro Oikawa

Kenichi Sato

Shogo Kamakura

A readout circuit for reading out an output current from a photoelectric conversion element which collectively outputs currents generated in a plurality of pixels, each of which includes an avalanche photodiode, includes a current mirror circuit configured to receive the output current and output first and second currents having magnitudes in proportion to the output current, a photon counting circuit configured to count the number of photons incident on the photoelectric conversion element on the basis of the first current, an integral circuit configured to integrate the second current to generate a voltage signal, and a signal processing unit configured to determine a magnitude of light incident on the photoelectric conversion element on the basis of a counting result output from the photon counting circuit and a magnitude of the voltage signal output from the integral circuit.

Readout circuit

A radiation image detecting device includes a photodetecting element that detects fluorescence light, and a prism that is disposed on an optical path of excitation light traveling toward an imaging plate and between the photodetecting element and the imaging plate. The prism includes, as surface thereof, a side face that is opposed to the imaging plate, and a side face and a side face that are inclined relative to the side face. The prism is disposed so that the excitation light incident through the side face propagates inside and is output from the side face and so that reflection from the imaging plate incident through the side face propagates inside and is output from the side face. The photodetecting element is disposed so as to be opposed to a region different from a region where the reflection from the imaging plate is output, in the surface of the prism.

Radiation image detection device

A radiological image reading device includes a MEMS mirror that scan a recording medium on which a radiological image is recorded with excitation light; a light detecting element that includes a plurality of channels, each channel including a photodiode array, and detects light emitted from an irradiation position of the excitation light on the recording medium; a MEMS mirror driving circuit that determines as a light detection channel to detect the light, a channel corresponding to the irradiation position of the excitation light, out of the plurality of channels; and a reading circuit that reads the detection result of the light from the channel determined by the MEMS mirror driving circuit.

Device for reading radiological images

A reverse bias voltage is applied to a photodiode array provided with a plurality of avalanche photodiodes operated in Geiger mode and with quenching resistors connected in series to the respective avalanche photodiodes. Electric current is measured with change of the reverse bias voltage applied, and the reverse bias voltage at an inflection point in change of electric current measured is determined as a reference voltage. A voltage obtained by adding a predetermined value to the determined reference voltage is determined as a recommended operating voltage.

Photodiode array, method for determining reference voltage, and method for determining recommended operating voltage

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Hamamatsu, Japan

Hiroki Suzuki